US1270770A - Lens-grinding machine. - Google Patents

Description

F. W. BARNES.

LENS GRINDING MACHlNE APPLICATION mfp MAR. 24. |916.

l ,276,770. Patented July 2, 1918.

` be made use of in preparing photogr UNITED STATES PATENT OFFICE.

FREDERICK W. BARNES, OF ROCHESTER, NEW YORK, ASSIGNOR T0 EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION 0F NEW YORK.

LENS-@BINDING MACHINE.

Bpecioation of Letters Patent.

Patented July 2, 1918.

To all whom t may concern:

Be it known that I, FREDERICK W. BARNES of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Lens- Grinding Machines; andl I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon.

My present invention relates to grinding machines and -more particularly to machines for grinding lenses and it has for its object to provide a machine of this character adapted for grinding and finishing off the edge surfaces of lenses in a safe and expeditious manner. The improvements are directed in part toward providing a `simple and eflicient means for beveling ofl the corner of the glass at the point where the lateral edge surface joins the polished or optical surface and to accomplishing this in such manner that there is no danger of impai'rng the optical surface. To these and other ends the invention resides in certain improvements and combinations of parts all as will be hereinafter more fully described,

lcoperation of the beveling grinder with the lens or work-piece. 4

Simllar reference numerals throughout the several lviews indicate the same parts.

Although the invention is not necessarily so restricted in its application, it can aphic lenses. These lenses, as camera objectwes,

I0 are usually set in a tube known as a lens yrately and to the diameter of whic tube which they are made to fit ver accuthe are carefully ound down. In seating thelii withinthe tu e, it is helpful if the lenses are devoid of sharp corners or edges having a tendency to catch upon minute burs or other inequalities operating to obstruct their entrance. For these reasons, I have found it expedient to lbevel or remove at least one corner edge of the lens and the machine illustrated herein was designed for that particular purpose which it accomplishes 'without requiring a separate operation to the extent that one handling or setting up of the lens is sufficient to carry it through both the beveling and edge grinding treatments.

Referring more particularlv to the drawing, the machine of this em turret machine, that is, one in which previously inserted lenses are being ground while the operator is utilizing the time thus consumed by setting up other lenses for subsequent grinding. It consists of a shiftable spindle head 1 turning upon a shaft 2 journaled in the base 3 and carrying four work spindles 4 mounted in bearings 5. The successive positions of the Work spindles are respectively indicated by the letters A, B, C, and D 1n Fig. 3. The head 1 is shifted by hand in the direction indicated by the arrow and A is the idle position of the spindles. The position Bis that in which the lenses or work pieces are applied and I have shown a lens indicated at 6 upon each spindle. The lens is stuck on to the spindle in a properly centered position by means of pitch or any suitable temporary cement and to cause its rotation for centerm purposes, namely, to bring the geometrica center of its previously ground optical faces into coincidence wit-h the axis of the spindle, the opposite end of the spindle projecting from the bearing 5 is provided with a clutch element 7 coperating temporarily with a similar clutch element 8 on a shaft 9 carried in a stationary bearing 10 on the support 3, the said shaft being provided with a pulley 11 (Fig. 2) and continuously driven by a belt 12.

diment is a When the lens or work-piece is properly centered in this manner,'the head 1 is shifted to carry the spindle to position C for treatment 'by the bevel grinder 13 herein- .speed through gearing 17, 18, 19 and 20,

the last named gear takingv motion from a worm 21 driven by a belt 22 and pulley 23. A shaft 24 carrying this gear 20 is provided on its opposite en'd with a clutch memfber similar to the clutch vmem'ber 14 but not shown herein and driven at the same s eed which shaft and clutch member are in a inement with theD position of the spindle so that the latter may be similarly rotated in that position also. 'W hen disposed at D, the lens orwork piece is acted upon by an edge grinder 25 following the beveling operation and -this edge grinder finishes'off the lens so that it can ,be removed when arriving again atposition A or at position B, if more convenient.

The beveling grinder 13 is preferably a diamond wheel with a rounded cuttingA face, as shown, and its shaft is carried ina bear'- v ing 26 on asliding bracket 27 vertically adjustable by means of a micrometer screw A28. The bracket 27 is in turn carried by a horizontally sliding bracket 29 on a supporting arm 30 extended from the general support 3 and such bracket 29 may be adjusted by means of a micrometer screw 31. These adjusting mechanisms d0 not require more minute description as their .function is merely to give thewheel 13 mobility in both the direction ofI its axis and laterally thereof; It is essential, however, that the grinder 13 revolve in a plane disposed angularly to the plane of rotation of the work piece 6 and of its -carrying spindle 4 and it preferably rotates in the plane of the axis of the said spindle 4 when the latter is in the position C. The work-piece is carried into contact with the wheel by theA rotation of the shifting head `1 and the wheel being rounded, as previously described, it readily cuts its' waythrough to a proper position relatively to the workpiece as the latter thus approaches it from lthe side. The work-piece revolves at a relatively slow speed' 'as soon as the clutch elements 7 and 14'are in engagement with each otherrwhilegthe grinder 13 travelsv at a relatively high rate of speed. Further adapted to contact with each' more, it will be noted that as the work-piece and wheel 13 are traveling in transverse planes, there is a tendenc of the dislodged particles resulting from t e grinding action that causes the cutting or grinding face or.

surface of the wheel to clear itself and the cutting contact is distributed more generally over the surface of the wheel than would be the case with other possible relative dispositions of the wheel and workpiece. It is also preferableto rotate this grinder 13 in the direction indicated by the arrows, namely, so thaty the cut is taken in a direction outwardly from the axis of the work spindle 4 and of the work-piece or from the optical surface toward the edge surface `of the lens. When so effected, the cut cannot possibly chip or mar the 4adjacent optical surface and any chipping that does occur onthe edge surface (which is then in a rough or unfinished state) will be removed by the subsequent action of the edge grinder 25.

This` edge grinder 25 is also preferably a diamond wheel but may have a cylindrical cutting periphery, as shown, and its shaft 32 is carried by a' bearing 33 ona swinging arm 34 and is continuously driven by a belt 35 and a pulley r36 on the outer end of; `such shaft 32. The swinging yarm 34 is -pivoted to the base 3 at 37 and held against an.l adjustable stop 38 Aby a cord 39 passing over a small pulley 40 and attached to a weight 43. As the workpiece leaves the position C after being beveled as described', and is carried to the position D forfcoperation with the edge grinder 25,

as `described,the latter is preferably thrust backward momentarily to an inoperative position by swinging the arm 34 and then is allowed to come gently into contact with the edge of the lens or work-piece 6 `where it is yieldingly held by the weight on the cord 39, the work-piece taking the thrust until itv is ground down to the proper diameter, at which point'the wheel is halted by contact of the arm 34 with the adjustable stop 38. The wheel Aor edge grinderj25 and the work-piece 6 rotate against each other, thatis, in the same direction but in opposite directions locally at the point of pntact, as indicated by the arrows in If it 'is desired to lock out the edge grinder 25, as for instance, when the beveling operation is to 'be performed, alone,.a latchy v41 on the .swinging'arm 34 is hooked over vlan arm. 42 onv the base 3 andthe tendency of the weight overcome.

I 'claim as'` my invention:

In a lens grinding machine, thev combination'with a revoluble support, a pluralityk of rotary-work supports on said revoluble which is arranged in substantiall the same operations, .and lother means for succesplane with the faces of sald wor supp'orts sively rotatmg said supports for centering 'and another of which is arranged in aplane the work thereon.

substantially perpendicular thereto and FREDERICK BARNES. adapted to coperate with different pieces Witnesses:

.of Work simultaneously, means wfor rotat- RUSSELL B. GRIFFITH, ing the work supports during the grinding AGNES Nnsrr BIssnLL.-

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